1. Field of the Invention
The present invention relates to a method and device for loading solid matter into bags which are continuously and rectilinearly conveyed in the horizontal direction with the bags in a vertical attitude and with the mouths of bags facing upward.
2. Prior Art
Generally, in solid matter loading guide devices used in bag-filling packaging machines, a fixed-quantity measuring device, etc. is disposed above the bag-filling packaging machine. A predetermined quantity of solid matter discharged from an opening in the lower end of a fixed chute which is installed in the fixed-quantity measuring device is caused to drop into the bags via a funnel-form guide member (hopper), etc. installed in the bag-filling packaging machine while the solid matter is guided by the inside surface of the hopper.
In order to perform this operation, the opening opened in the upper end of the hopper must be disposed so as to face the opening opened in the lower end of the fixed chute. In addition, the opening in the lower end of the hopper must face the mouth of the corresponding bag, and loading must be performed in this state. Furthermore, in order to accomplish the loading of solid matter in a secure and stable manner, loading is in some cases performed in a state in which the opening in the lower end of the hopper is inserted into the mouth of the corresponding bag.
In the case of a continuous conveying type bag-filling packaging machine in which respective packaging steps are performed while the bags are continuously conveyed, the opening in the upper end of the hopper must face the fixed chute of the fixed-quantity measuring device while the opening in the lower end of the hopper faces the mouth of the corresponding bag that is being continuously conveyed, and the hopper must move in synchronization with the conveying movement of the bags. Naturally, after loading, the hopper must be moved in the opposite direction and returned to its original position. Furthermore, in cases where the opening in the lower end of the hopper is inserted into the mouth of the corresponding bag during loading, the hopper must be raised during the return movement so that the hopper does not interfere with the bags being conveyed.
Conventionally, there are two types of such hoppers as described below:
(1) Reciprocating Motion Type Hoppers
These are hoppers having a large opening in the upper end, and they are installed so as to reciprocate and to be freely raised and lowered. During the advancing motion of the hopper, the hopper is lowered and moved in synchronization with the bags in the conveying direction of the bags in a state in which the opening in the lower end of the hopper is inserted into the mouth of the corresponding bag (motion in the conveying direction of the bags is taken as an advancing motion). Near the final end position of the advancing motion, the hopper is raised; and then the hopper is moved in the opposite direction without any interference between the opening in the lower end of the hopper and the bags that are being conveyed (this motion in the opposite direction is taken as the return motion), so that the hopper returns to the initial end position of the advancing motion.
However, the opening in the upper end of the hopper must be formed with a considerable length in the direction of the reciprocating motion (a length equal to or greater than the distance of the reciprocating motion). Accordingly, the size of the hopper tends to be large, and the size of the mechanisms used for the reciprocating motion and the raising and lowering of the hopper is also large. As a result, the cost of the apparatus increases. Such a large size also hinders an increase in the speed of the bag-filling packaging machine. Furthermore, as the size increases, there is also an increase in vibration and noise, thus deteriorating the working environment.
(2) Reciprocating Swinging Motion Type Hoppers
These are hoppers that are installed so that the hopper is free to perform a reciprocating swinging motion about a point in the vicinity of the center of the upper end of the hopper and so that the hopper is freely raised and lowered. During the advancing motion, the hopper is lowered, the opening in the lower end of the hopper is moved over a circular-arc-form track in synchronization with the conveying of the bags, and at an intermediate position on this circular-arc-form track, the opening in the lower end of the hopper is inserted into the mouth of the corresponding bag. After arriving at the final end position of the advancing motion, the hopper is raised; and it performs a return motion without any interference between the opening in the lower end of the hopper and the bags that are being conveyed, so that the hopper returns to the initial end position of the advancing motion.
However, since the opening in the lower end of the hopper is inserted into the mouth of the bag while the hopper is in inclination, erroneous insertion in which the opening in the lower end of the hopper catches on the upper edge of the bag tends to occur. Furthermore, the opening in the lower end of the hopper is inserted into the mouth of the corresponding bag for only a part of the entire distance of the advancing motion (in the vicinity of an intermediate position in this advancing motion), so that the ratio of the insertion time (during which loading takes place) to the advancing motion time is small; as a result, loading mistakes tend to occur. Alternatively, in order to increase time for insertion, it is necessary either to lower the speed or to increase the size of the hopper and increase the distance of the reciprocating swinging motion. In either case, an increase in the speed of the bag-filling packaging machine is hindered, and the size of the bag-filling packaging machine tends to be large.
The present is to solve the problems encountered in the conventional hoppers (solid matter loading guide devices) used in continuous conveying type bag-filling packaging machines.
It is, therefore, an object of the present invention to provide a solid matter loading method and a loading guide device that increase the speed of loading of a solid matter without any need for an increase in size of hoppers and hopper driving mechanism, eliminate solid matter loading errors, and eliminate erroneous insertion of the lower end of a hopper into the mouth of a bag.
The above object is accomplished by a unique solid matter loading method of the present invention for a continuous conveying type bag-filling packaging machine, and in the preset invention:
upon loading a solid matter into bags which are continuously and rectilinearly conveyed in a horizontal direction with the bags in a vertical attitude in the continuous conveying type bag-filling packaging machine, the solid matter is loaded into a bag by:
an upper hopper which performs a reciprocating swinging motion along a conveying direction of the bags and about a point located near a center of an upper portion of the upper hopper, and
a lower hopper which is positioned beneath the upper hopper and performs a reciprocating motion along the conveying direction of the bags; wherein
when the upper hopper swings in the conveying direction of the bags and the lower hopper is moved in the conveying direction of the bags,
the upper hopper swings and the lower hopper is moved in synchronization with a conveyance of the bag, and
the solid matter drops and is loaded into the bag by being guided by the upper hopper and lower hopper.
In this method, it is preferable that the lower hopper be movable upward and downward. Also, when the lower hopper is moved in synchronization with the conveyance of the bag in the conveying direction of the bags, the lower hopper is moved downward to a position where an opening at a lower end of the lower hopper is inserted into the mouth of the bag.
In addition, it is also preferable that an opening member be inserted into the mouth of the bag at the time of loading of the solid matter, thus opening the mouth of the bag and keeping the mouth opened.
The above object is further accomplished by a unique structure for a solid matter loading guide device in a continuous conveying type bag-filling packaging machine, the solid matter loading guide device loading a solid matter into bags that are continuously and rectilinearly conveyed in a horizontal direction with the bags in a vertical attitude; and in the present invention the solid matter loading guide device includes:
an upper hopper which performs a reciprocating swinging motion along a conveying direction of the bags and about a point located near a center of an upper portion of the upper hopper, and
a lower hopper which is positioned beneath the upper hopper and performs a reciprocating motion along the conveying direction of the bags; wherein
the lower hopper performs a reciprocating motion in synchronization with a reciprocating swinging motion of the upper hopper, with an opening in an upper end of the lower hopper being caused to face an opening in a lower end of the upper hopper, and
when the lower hopper is moved in the conveying direction of the bags, the lower hopper is moved in synchronization with the conveyance of the bags with the opening in the lower end of the lower hopper being caused to face the mouth of a bag.
In this structure, it is preferable that a plurality of sets of the upper hopper and lower hopper are disposed along the conveying direction of the bags, and respective sets of the upper hopper and lower hopper are disposed at intervals which are equal to a conveying pitch of the bags.
Also, the lower hopper is preferably movable upward and downward, so that when the lower hopper is moved in the conveying direction of the bags, the lower hopper is moved downward to a position where an opening at the lower end of the lower hopper is inserted into the mouth of the bag. At all other times, the lower hopper is raised to a position where the lower opening of the lower hopper is out of the mouth of the bag.
In addition, it is preferable that the solid matter loading guide device further include an opening member that performs a reciprocating motion along the conveying direction of the bags in synchronization with movements of the upper and lower hoppers and makes a reciprocating motion between a position where it is inserted in the mouth of the bag and a position where it is retracted out of the bag. When the opening member is moved in the conveying direction of the bags, the opening member is moved to the position of insertion, opens the mouth of the bag and maintains the mouth opened. At all other times, the opening member is at its retracted position.